Introduction | GSM | DECT | PCS1900 |
GSM Application Benchmarks
1. GSM High Side Injection
Figure 15 Application circuit, GSM high side injection
GSM 1st LO high side injection was simulated with the following design conditions.
| VCC | 3.3 V |
|---|---|
| V CP, V VCO | 5 V |
| Comparator frequency | 200 kHz |
| Prescaler divide ratio | 64/65 |
| Reference oscillator | 13 MHz, -3 dBm |
| RF out | 1018 MHz |
| Ambient temperature | 25°C |
| VCO | Murata MQE 042-1016 (Kv = 20 MHz/V) |
Parts list:
| C1 | 100 pF |
|---|---|
| C2 | 10 nF |
| C3 | 10 µF |
| C4 | 100 pF |
| C5 | 33 pF |
| C6 | 33 pF |
| C10 | 100 pF |
| C11 | 10 µf |
| R3 | 0 Ω |
| R4 | 51 Ω |
| R5 | 47 κΩ |
| R6 | 47 κΩ |
| R7 | 47 κΩ |
| R8 | 18 Ω |
| R9 | 18 Ω |
| R10 | 18 Ω |
Loop filter:
| C7 | 2 nF |
|---|---|
| C8 | 20 nF |
| C9 | 330 pF |
| R1 | 15 κΩ |
| R2 | 2.2 κΩ |
| Phase error | RMS value | Peak value | Unit |
|---|---|---|---|
| @1018 MHz | 2.2 | 6.8 | degrees |
| Hopping time | Measured value | Unit | Remarks |
|---|---|---|---|
| 1005 MHz → 1031 MHz | 486 | µs | |
| 1031 MHz → 1005 MHz | 427 | µs |
- 1
- Close to measurable limit
Figure 16 - Spurious performance at 1018 MHz
Figure 17 - Phase noise performance; C/N= -71.0 dBc/Hz, maximum within loop bandwidth
Figure 18 - Phase noise performance @ Δ f= 1MHz from carrier; C/N= -139.3 dBc/Hz « -146.3 dBm/Hz
Figure 19 - Phase noise performance @ Δ f= 10 MHz from carrier; C/N= -147.6 dBc/Hz « -154.6 dBm/Hz (close to measurable limit)
Figure 20 - Hopping time 486µs for frequency step 1005MHz → 1031MHz (Measurement triggered 100µs after PLL was programmed, therefore the marker readout shown on top is 100µs longer than the actual hopping time)
Figure 21 - Hopping time 427µs for frequency step 1031MHz → 10305MHz (Measurement triggered 100µs after PLL was programmed, therefore the marker readout shown on top is 100µs longer than the actual hopping time)
Figure 22 - Phase error @1018MHz, RMS value: 2.2°, peak value: 6.8°
